The present invention is directed to bicycles and, more particularly, to a bicycle rear derailleur.
Bicycles typically include a frame, front and rear wheels, pedals that are used to rotate one or more front sprockets, a plurality of rear sprockets mounted to the rear wheel, and a chain that engages one of the plurality of front sprockets and one of the plurality of rear sprockets. A front derailleur mounted to the frame in close proximity to the plurality of front sprockets is used to shift the chain among the plurality of front sprockets, and a rear derailleur mounted to the frame in close proximity to the plurality of rear sprockets is used to shift the chain among the plurality of rear sprockets. The rider typically uses manual, electric, or hydraulic control devices to control the front and rear derailleurs.
Small bicycles that have a frame capable of folding upon itself to facilitate carrying on public transportation or storage at work facilities are becoming more popular. Because such bicycles are carried and stored in crowded places, they should be very compact. Thus, the sizes of the frame and wheels are minimized accordingly. Very often the frame folds in half in the middle so that the front wheel is placed adjacent to the rear wheel. Thus, the rear derailleur should be as compact as possible so as not to protrude excessively laterally and impact the front wheel, thereby preventing compact folding of the frame. Furthermore, the rear derailleur should not be so large or mounted so low on the frame as to strike the ground as the bicycle is being ridden.